Thinking Mathematically (6th Edition)

by
Blitzer, Robert F.

Chapter 5 - Number Theory and the Real Number System - 5.1 Number Theory: Prime and Composite Numbers - Exercise Set 5.1 - Page 256: 10

Answer

The number 5,941,221 is divisible by: 3
It is not divisible by: 2, 4, 5, 6, 8, 9, 10, or 12.

Work Step by Step

The number 5, 941, 221 is divisible by:
a. 2 --No. It is not even.
b. 3 --Yes. The sum of its digits (5 + 9 + 4 + 1 + 2 + 2 + 1 = 24) is divisible by 3.
c. 4 --No. The last two digits (21) make a number that is not divisible by 4.
d. 5 --No. The ones digit is not a zero, nor is it a five.
e. 6 --No. The number is not divisible by both 2 and 3.
f. 8 --No. The last three digits (221) make a number that is not divisible by 8.
g. 9 --No. The sum of the digits is not divisible by 9.
h. 10 --No. The ones digit is not a zero.
i. 12 --No. The number is not divisible by 3 and 4.